1. Field of the Invention
The present invention relates to a method for analyzing structures of mucosa samples, and in particular relates to a method for analyzing the mucosa samples with optical coherence tomography.
2. Description of the Related Art
The majority of oral cancers are found to develop from oral premalignant lesions such as leukoplakia, erythroplakia, erythroleukoplakia, dysplasia, and carcinoma in situ. Due to the high malignant transformation rates for oral premalignant lesions, early diagnosis and early treatment are important. In order for a correct pathological diagnosis, a suspicious oral lesion may need multiple biopsies to avoid misdiagnosis of the most severe part of the lesion. For reducing a patients' pain and suffering from multiple biopsies, one of the best non-invasive technique to select the most appropriate sites for biopsy is to use optical coherence tomography (OCT) imaging to detect oral precancers and cancers.
Although the time-domain configuration of OCT has been applied in a variety of medical and biological applications, such a configuration has several restrictions, including limited imaging speed. Recently, OCT systems based on Fourier-domain detection have been widely implemented to speed up imaging speed. OCT systems based on Fourier-domain detection may include two techniques, either the spectral-domain OCT (SD-OCT) or the swept-source OCT (SS-OCT), wherein both of them obtain the depth structure information of a detected object by spectrally resolving the interference signal. A Fourier-domain OCT system has the advantages of higher imaging sensitivity and faster imaging speed when compared with a time-domain system. In the SD-OCT technique, normally a detector array, such as a charge-coupled device (CCD), is needed. However, slow development of CCDs has limited the application of the SD-OCT technique. On the other hand, the rapid development of the sweeping-frequency laser has led to a spectral coverage of the SS-OCT technique covering the entire biological window, from 1300 nm through 1050 nm to 850 nm. Nowadays, SS-OCT systems are widely used for various biomedical applications.